RAMALLAH, West Bank — Under fire at home and abroad, President Mahmoud Abbas of the Palestinian Authority moved on Tuesday to solidify his decade-long hold on power with a party conference that had already been purged of most of his opponents.

The carefully selected delegates wasted little time in formally re-electing Mr. Abbas as the leader of Fatah, the party that controls the Palestinian Authority in the West Bank. “Everybody voted yes,” a spokesman for Fatah, Mahmoud Abu al-Hija, told reporters who had not been allowed into the conference hall for the decision.

The conference, Fatah’s first in seven years, comes as the Palestinians face economic troubles, violent clashes among competing clans and the continuing Israeli occupation of the West Bank. Critics complain that Mr. Abbas’s leadership has grown insular and out of touch. He convened the conference to demonstrate his continued grip on the Palestinian Authority and to restock the Fatah party leadership with allies.

“It represents a renewal of legitimacy; there is no doubt about that,” Nasser al-Kidwa, a former Palestinian foreign minister, said in an interview. Mr. Kidwa is a nephew of Mr. Abbas’s predecessor, Yasir Arafat, who is still revered by many Palestinians. The vote at the conference, Mr. Kidwa said, “turns the page on some of our internal problems that have existed in recent times.”

Omar Shalabi, a party member attending the conference, said that Fatah activists wanted to bolster Mr. Abbas in the face of the challenges before him. “We assured the president that we are with him,” Mr. Shalabi said.

Even Mr. Abbas’s supporters, though, said change was necessary, and they expressed hope that he would bring in fresh blood. “We need a new strategy because we are facing a very hard situation,” said Hatem Abdul Qader, a former Palestinian government minister. “We need to think out of the box. We need new hope.”

Mr. Abbas, 81, who was treated recently for heart problems, has been a central figure in Fatah for decades. He was a lieutenant to Mr. Arafat and a member of the team that negotiated the Oslo accords with Israel in the 1990s; he ascended to the Palestinian leadership after Mr. Arafat’s death in 2004. In the 12th year of what was initially supposed to be a four-year term, Mr. Abbas has lashed out at opponents, and they have been ousted from party positions and at times arrested.

Mr. Abbas was once a favorite of Americans and Arab allies, but they have grown increasingly disillusioned with him. Now he is caught between Palestinians who consider him too close to the Israelis, and Israelis who say he is no partner for peace. His own would-be state is split between the West Bank, where he governs amid the Israeli occupation, and Gaza, which was seized nearly a decade ago by the more militant Hamas faction.

Some Palestinian activists had wondered whether Mr. Abbas would use the conference to give up at least one of the three titles he holds — leader of Fatah, leader of the Palestine Liberation Organization and president of the Palestinian Authority. But he made clear on Tuesday that he would not.

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The Palestinian leader Mahmoud Abbas spoke at the party congress, being held for the first time since 2009.Published OnNov. 29, 2016CreditImage by Reuters

What remained unclear was whether Mr. Abbas would lay out a succession plan during the gathering, which was scheduled to last at least five days. He has rebuffed calls from Arab nations and Palestinian activists for him to groom a successor. Because of the split with Hamas, it is not certain who would be next in line to lead the Palestinian Authority if Mr. Abbas were incapacitated.

Mr. Abbas planned to address the conference on Tuesday evening, and he sat onstage and appeared in good spirits. At the last minute, though, he postponed his speech until Wednesday. Some veteran observers doubted that he would use the occasion to identify a possible heir, if only because doing so might set up another power center in the West Bank that would inevitably undercut his authority.

Allies of Mr. Dahlan, and even some Palestinians who were only thought to be his allies, have been purged from Fatah or arrested, and competing factions have engaged in violent clashes. Diana Buttu, a former Palestinian official who is now a critic of Mr. Abbas, named 10 party figures who had been ousted recently.

“To me, the story is who is not at the conference,” said Grant Rumley, a scholar at the Foundation for Defense of Democracies in Washington and a co-author of a forthcoming biography of Mr. Abbas. “This conference will formalize the split within his own party.”

Some supporters of Mr. Abbas played down the divisions. “This is Israel’s strategy, for us to butt heads with each other,” said Jamal Muheisen, a member of the Fatah central committee. “Even though we have difficulties with other parties, everybody recognizes Mahmoud Abbas as the president of the Palestinian people.”

Several potential successors or their representatives attended the conference, including Mr. Kidwa and the wife and son of Marwan Barghouti, a popular figure who is serving multiple life terms in an Israeli prison for murder.

The son, Qassam Barghouti, 30, said that Palestinians were “very committed” to his father, but that the goal for now was bringing the party together. “After the divisions we’ve been seeing in the last two to three years, what we saw shows that Fatah is united,” he said during a break in the conference.

Mr. Abbas hoped that the event would be a step toward reconciliation with Hamas. Ahmed Haj Ali, a senior Hamas legislator, was invited to address the conference.

“We are partners in this homeland, our cause, struggle and resolutions,” he told the delegates, “and we in Hamas are ready to fulfill all requirements of this partnership with you and all factions.”

A version of this article appears in print on , on Page A10 of the New York edition with the headline: Abbas, Re-elected as Fatah Leader, Moves to Solidify Power in Face of Turbulence. Order Reprints | Today’s Paper | Subscribe